Applied Loads and Stability of Steel and Steel-Concrete Composite Bridges - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 153

the structure (e.g., portal frame and continuous beams), friction at rotational
bearings, and nonlinear geometric effects (second-order effects). EC1 [ 3.3 ]
specifies two approaches for vertical linear component (Approaches 1 and 2).
In Approach 1, the effect of vertical temperature differences should be con-
sidered by using an equivalent linear temperature difference component
with

T M,cool . These values should be applied between the
top and the bottom of the bridge deck. Values of

D T M,heat and D

T M,cool
to be used in a country may be found in its National Annex. Recommended
values for

D T M,heat and D

T M,cool are given in Table 3.12 .
In Approach 2, vertical temperature components with nonlinear effects
should be considered by including a nonlinear temperature difference com-
ponent. Values of vertical temperature differences for bridge decks to be
used in a country may be found in its National Annex. Recommended
values are given in EC1 [ 3.3 ] and are valid for 40 mm surfacing depths
for deck type 1 and 100 mm for deck types 2 and 3. For other depths of sur-
facing, see Annex B of EC1 [ 3.3 ] . Vertical temperature differences for bridge
decks depends on “heating,” which refers to conditions such that solar radi-
ation and other effects cause a gain in heat through the top surface of the
bridge deck, and “cooling,” which refers to conditions such that heat is lost
from the top surface of the bridge deck as a result of reradiation and other
effects. In general, the temperature difference component need only be con-
sidered in the vertical direction. In particular cases, however (for example,
when the orientation or configuration of the bridge results in one side being
more highly exposed to sunlight than the other side), a horizontal temper-
ature difference component should be considered. The National Annex may
specify numerical values for the temperature difference. If no other informa-
tion is available and no indications of higher values exist, 5 C may be
recommended as a linear temperature difference between the outer edges

D T M,heat and D

Table 3.12 Values of Linear Temperature Difference Component for Different Types of
Bridge Decks for Road, Foot, and Railway Bridges Recommended by EC1 [ 3.3 ]

Top Warmer than Bottom Bottom Warmer than Top
DT M,heat ( C) DT M,cool ( C)

Type of Deck

Type 1: steel deck 18 13

Type 1: composite deck 15 18

Type 1: concrete deck
Concrete box girder 10 5

Concrete beam 15 8

Concrete slab 15 8